Step and repeat apparatus



March 21, 1961 PELL 2,975,694

STEP AND REPEAT APPARATUS Filed Sept. 22, 1958 VACUUM TAIL: covn 1 sznsrrlzso E PRESS PLATE VACUUM TABLE 2,975,694 Patented Mar. 21, 1961 [ice STEP AND REPEAT APPARATUS Kenneth M. Pell, 120 S. Hayford Ave., Lansing, Mich. Filed Sept. 22, 1958, Ser. No. 762,570

1 Claim. (Cl. 95-77) This invention relates to a process and apparatus for exposing in register multiple images of a composited negative or positive onto a sensitized metal press plate and more particularly to a process and apparatus which eliminates the need for costly step and repeat machines in small printing shops and provides means for small printing shops to do multiple image printing hitherto reserved to the larger printing companies.

Smaller printing shops have been unable to accept work or enter competitively into fields whereby composited negatives or positives become multiple images on a press plate in order to accomplish large volume printing orders. The essence of successful creation of multiple images on a press plate is the maintenance of completely accurate register during the multiple exposure process. The need for such an accurate register has required use of an expensive step and repeat machine. The large cost of a step and repeat machine for all practical purposes eliminated the small print shop operator from a substantial portion of the printing and multiple exposure photography field. Y

A need, therefore, arose in the printing and photography field for an inexpensive process and apparatus which would permit successful creation of multiple images of alcomposited negative or positive onto a sensitized press p ate.

It is therefore an object of this invention to provide an inexpensive method and apparatus whereby a composited negative or positive may be exposed so as to create multiple images onto a press plate.

Another object of this invention is to provide a method for exposing multiple images of a composited negative or positive in repetitively accurate register onto a press plate.

A still further object of this invention is to provide a simple trouble free structure capable of high production and economical maintenance.

Other objects and advantages found in the construction of my invention will be apparent from a considera tion of the following specification in connection with the appended claim and the accompanying drawings.

In the drawings:

Figure 1 is an exploded schematic view illustrating the relative positioning of the various elements of this invention in relation to the vacuum table and vacuum table cover.

Figure 2 is a top view of the master plate sheet illustrating its positioning marks and the press plate in position thereon.

Figure 3 is a top view of the transparent master blueline step sheet illustrating a positive or negative in position thereon and further showing in phantom line the succeeding positions of the positive or negative during the multiple exposure process.

Figure 4 is a top break away view illustrating the relative positioning of the various elements of this invention in their use position on the top surface of a vacuum table.

General description In general this invention relates to the photography and photo-lithography field. In order to produce artistic copy containing photographs for advertising purposes, it is first necessary to produce layouts. These are produced by creating a line negative upon which inserts are placed.

A silver print proof is made of the layout to show the customer for his approval. After customer approval, layouts are contacted in order to obtain a composited negative (or positive) of the complete job.

A check is then made of the quantity of run and quantity of sheets to press. With this information, determine: tion is then made of the number of images of the composited negative which must be made upon the press plate.

It is imperative that each image must be in register and hence the negative (or positive) must be accurately positioned before an exposure is made.

The importance of this requirement is emphasized in color work where repetitive accurate register is necessary to produce satisfactory and attractive work. In addition, repetitive accurate register is important in re-run work where certain color images are run to the exclusion of others.

An element of the instant invention is a master plate sheet which is provided with a base reference line and a center mark that are utilized to accurately positiona press plate upon the master plate sheet. The master plate sheet is mountable'upon the rubber back of a vacuum printing frame and the press plate is positionable accurately upon the master plate sheet so as to receive multiple images of a composited negative or positive.

A mating master blue-line step sheet is provided for the master plate sheet. The master blue-line step sheet is transparent and is provided with numbered horizontal and vertical blue grid lines to enable one to position cornposited negatives or positives thereon with relative ease and repetitive accuracy.

The master plate sheet is positionable on the vacuum table and the press plate is referenced thereon. The master blue-line step sheet may be repetitively positioned over the master plate sheet with accuracy so as to place a positive or negative in direct contact with the press plate. Thus, multiple images of the positive or negative are made upon the press plate by moving the negative or positive to pre-determined positions on the master blue-line step sheet.

Specific description The master plate sheet 11 is a substantially rectangular flexible sheet of transparent plastic. The master plate sheet 11 is provided with a longitudinal base register or reference line 12 and vertical center mark 13, but it is within the scope of this invention to utilize any suitable type of reference points for the press plate 14.

The press plate 14 is made of metal having a photosensitive surface and is of a type commonly used in the printing field.

The master plate sheet 11 is provided with master plate sheet tabs 15 at each side. In the preferred embodiment the tabs 15 are provided with upright reference pins 16.

The master blue-line step sheet 17 is also a substantially rectangular sheet of transparent plastic. Numbered grid lines are provided on the blue-line step sheet 17 in the ratio of sixteen lines to the inch. However, it is within the scope of this invention to utilize any number of grid lines provided that they are accurately spaced on the blue-line step sheet 17. Blue-line step sheet tabs 18 are provided on the master. blue-line step sheet 17 and have holes 19 therethrough which engage the reference pins 16 of the master plate sheet 11 so as to always vacuum table and secured by strips of tape.

'3 v) insure repetitive accurate register of the master blue-line step sheet 17 over the master plate sheet 11.

The photographer or printer, predetermines the exact positioning of the composited negative 21 on the blue-line step sheet 17 during the exposure process which creates multiple images on the press plate.

In use, the master plate sheet 11 is mounted upon the The press plate 14 is then placed in position on the master plate sheet 11 and is centered by use of the reference lines 12 and 13, as shown in Figure 2.

The composited negative or positive 21 is then taped to the master blue-line step sheet 17, as shown in Figure 3.

Once the composited negative 21 is in position on the master blue-line step sheet 17, the master blue-line step sheet is then placed on the master plate sheet 11 so that the negative 21 is in contact with the press plate 14. The master blue-line step sheet 17 and the master plate sheet 11 are always in accurate repetitive register with each other because the pins 16 of the master plate sheet 11 engage the openings 19 of the master blue-line step sheet tabs 18. 7

It is thus seen that a sandwich is formed consisting of the master plate sheet 11, the press plate 14, the cornposited negative 21, and the master blue-line step sheet 17.

The vacuum table top 22 is then closed and the vacuum table 20 and the vacuum table top 22 form the outside of the sandwich. This relationship is shown in the exploded view of Figure 1.

An exposure is made of the composited negative 21 directly on to the press plate 14, thus creating the first image of the compositive negative 21 on the face of the press plate 14.

The master blue-line step sheet 17 is removed from the vacuum table 21) and the composited negative 21 is then moved to the next step position shown by phantom line blocks 23. This is shown in Figure 3. The master blueline step sheet 17 is then again placed over the master plate sheet 11 and a subsequent exposure is made on the press plate 14. This process may be repeated as many times as is necessary and accurate repetitive positioning of the negative or positive in relation to previous exposures is always insured.

It is thus seen that a simple apparatus is provided which provides a service hitherto available only through an expensive step and repeat machine. This high cost of such a machine has practically eliminated the small printer from a highly lucrative field.

Various modifications of the invention may be made without departing from the principle thereof. Each of these modifications is to be considered as included in the hereinafter appended claim unless this claim by its language expressly provides otherwise.

Having thus set forth the nature of my invention, I claim the following:

An apparatus adapted for the step and repeat reproduction of the samev film transparency comprising: a flat flexible rectangular master plate sheet provided at each end with a positioning pin tab having upwardly extending positioning pins mounted thereon; and a second fiat transparent flexible member of substantially the same size as said master plate sheet and having at each end positioning pin receiving tabs in register with and adapted to receive said positioning pins, said second member positioned on said master plate sheet in said register, said second member and said master plate sheet being adapted to receive therebetween a sensitized-press plate of substantially the same size coated with a photographic emulsion and a movable transparency overlying said sensitized plate so as to create an image upon said sensitized press plate upon exposure through said transparent member, said transparent memberhaving horizontal and vertical grid lines over the entire surface thereof, said grid lines being of a blue color to which said sensitized press plate is insensitive, said master plate sheet having press plate positioning lines thereon.

References Cited in the file of this patent UNITED STATES PATENTS 1,777,144 Innes Sept. 30, 1930 2,298,081 Cohen Oct. 6, 1942 2,610,413 Dasey Sept. 16, 1952 2,711,031 Kessler June 21, 1955 2,752,245 Hough et al. June 26, 1956 

